| 摘要 |
PURPOSE:To obtain the attenuation signal no change in waveform, by providing the detection circuit outputting the output when the voltage of capacitor charging and discharging with the switch is within a given range, and by performing charging or discharging other capacitor through gate switching with this output. CONSTITUTION:When the switch 1 is depressed, transistors TrT1 is turned on, constant current circuit 2 is operated, charging the capacitor C1. When the charging voltage exceeds Va, output is made from the comparator 3, turning on TrT3. When the charging voltage exceeds Vb, the comparator 4 makes output, turning of TrT2. Thus, TrT4, T5 are turned on and the capacitor C2 is charged up with the signal c in a short time. After the completion of charging, the attenuation signal d is outputted at the output terminal 8 through TrT6 and T7. When the modulation signal is fed from the terminal 9 via TrT8 connected to the base of TrT6, the signal e is outputted at the terminal 8. When the switch 1 is detouched, C1 is discharged and the signal c (B) is generated with the comparators 3 and 4, performing charge and discharge of C2. |
